A throttle plate for a throttle body or carburetor is conventionally constructed with a flat metal plate pivotally held in place with a pivot shaft. The shaft holds the plate within the throttle bore for control of air intake for mixing with fuel and burning after being compressed within the engine cylinder. The ends of the shaft are secured to, and extend through, the carburetor or throttle body. One end is coupled to the throttle controller to vary the opening of the throttle plate to increase or decrease the amount of air fed to the intake port of the cylinder.
As air passes over the throttle plate the flow is somewhat interrupted by the discontinuity introduced by the bulging shaft extending across the middle of the plate. A conventional shaft holding a throttle plate is “D” shaped and riveted or screwed to the throttle plate. Smooth air flow is disrupted with a consequent loss in total air flow possible at wide-open throttle (WOT) for a given throttle body size. Thus, a need exists for a smoother flowing, more efficient air intake system.
In the case of fuel delivery systems, a specific throttle body is sized for the needs of a particular engine's fuel requirements. For an engine of a different displacement, a differently sized throttle body is provided. The need for various sizes results in increased part counts for a series of engines with resultant increases in cost and complexity. Furthermore, carburetors, throttle bodies, and throttle plates are typically constructed of metals such as aluminum, brass, and steel. These materials add weight to a vehicle and also result in costly part construction and assembly. The shaft and rivet or screw assembly also introduces an unnecessary chance for failure.